Dutch police have arrested 12 people in one of the country's biggest drug stings in recent years, officials said, according to BBC News.

The suspects, who include citizens from the U.S., Cape Verde and the Dutch Antilles, are accused of smuggling cocaine from the Caribbean via Amsterdam's Schiphol airport.

The gang also "planned to carry out assassinations," a police spokesman said without elaborating.

The arrests were part of countrywide raids involving more than 200 officers. Agents raided homes and businesses in the joint operation led by Dutch police as well as customs and tax officials.

“They confiscated quantities of cocaine and weapons,” police spokesman Robert Van Kapel said. “The international criminal network had used Schiphol airport to smuggle the drugs. It was one of the biggest actions against drug gangs in recent years.”

The cocaine is thought to have been smuggled by couriers swallowing the drugs, or by hiding it in freight containers.

Earlier this month, police arrested another 20 suspected cocaine smugglers at Schiphol.

In March, airport authorities confiscated 300 kilos (660 pounds) of cocaine from South and Central America with an estimated street value of 12m euros.